title: A horizontally polarizing liquid trap enhances the tabanid-capturing efficiency of the classic canopy trap.
abstract: Host-seeking female tabanid flies, that need mammalian blood for the development of their eggs, can be captured by the classic canopy trap with an elevated shiny black sphere as a luring visual target. The design of more efficient tabanid traps is important for stock-breeders to control tabanids, since these blood-sucking insects can cause severe problems for livestock, especially for horse- and cattle-keepers: reduced meat/milk production in cattle farms, horses cannot be ridden, decreased quality of hides due to biting scars. We show here that male and female tabanids can be caught by a novel, weather-proof liquid-filled black tray laid on the ground, because the strongly and horizontally polarized light reflected from the black liquid surface attracts water-seeking polarotactic tabanids. We performed field experiments to reveal the ideal elevation of the liquid trap and to compare the tabanid-capturing efficiency of three different traps: (1) the classic canopy trap, (2) the new polarization liquid trap, and (3) the combination of the two traps. In field tests, we showed that the combined trap captures 2.4-8.2 times more tabanids than the canopy trap alone. The reason for the larger efficiency of the combined trap is that it captures simultaneously the host-seeking female and the water-seeking male and female tabanids. We suggest supplementing the traditional canopy trap with the new liquid trap in order to enhance the tabanid-capturing efficiency.
authors.affiliation: Environmental Optics Laboratory, Department of Biological Physics, Physical Institute, Eötvös University, H-1117 Budapest, Pázmány sétány 1, Hungary.
authors.forename: Á
authors.initials: Á
authors.lastname: Egri
authors.forename: M
authors.initials: M
authors.lastname: Blahó
authors.forename: D
authors.initials: D
authors.lastname: Száz
authors.forename: G
authors.initials: G
authors.lastname: Kriska
authors.forename: J
authors.initials: J
authors.lastname: Majer
authors.forename: T
authors.initials: T
authors.lastname: Herczeg
authors.forename: M
authors.initials: M
authors.lastname: Gyurkovszky
authors.forename: R
authors.initials: R
authors.lastname: Farkas
authors.forename: G
authors.initials: G
authors.lastname: Horváth
mesh_terms: D000818:Animals; D004175:Diptera; D005260:Female; D007300:Insect Control / Q000295:instrumentation*; D008027:Light; D008297:Male